1. Field of the Invention:
There are two types of button perforating sewing machines. The first type (hereinafter referred to as the earlier perforation type) perforates cloth at an early step in the operation. The second type (hereinafter referred to as the later perforation type) perforates cloth at a later step in the operation.
The present invention relates to a presser bar lifter in a perforating sewing machine which can be adapted for use in either type machine.
2. Description of Prior Art:
The earlier type machine employs the following steps in succession: "SEWN CLOTH CLAMPING STEP", "BUTTON PERFORATING STEP", "CLOTH TENSIONING STEP", "FIRST FEEDING STEP", "SEWING STEP", "SECOND FEEDING STEP" and "SEWN CLOTH CLAMPING AND RELEASING STEP". The later type machine employs a different succession of steps: "SEWN CLOTH CLAMPING STEP", "CLOTH TENSIONING STEP", "FIRST FEEDING STEP", "SEWING STEP", "SECOND FEEDING STEP", "BUTTON PERFORATING STEP", and "SEWN CLOTH CLAMPING AND RELEASING STEP".
Thus, the earlier perforation type machine and the later perforation machine utilize steps which differ in the order or position of the "BUTTON PERFORATING STEP".